Hi! I just signed-up, & the question on the "Edit Profile" page has me confused!

Hi! My User Name is "Nuts4Mutts4Ever", but there is a pink bar below it that says that I have to add a NUMBER---my 'user name already has two "4"s in it, so will you please tell me what I did wrong? Also, I got another Newsletter sign-up for my "non-special" e-mail address, (it's the address I use for 'normal' things)--should I ignore that e-mail? PLEASE help!!
Love & Licks, "Jasper" &
Love, Donna, (aka--Nuts4Mutts4Ever)